Among US Medicare recipients, metabolic disorders contribute more to the burden of hepatocellular carcinoma (HCC) than any other risk factor, and the fraction of HCC caused by metabolic disorders has increased in the last decade. This according to a study of 10,708 patients with HCC and a 5% random sample of 332,107 cancer-free controls. Researchers found:

• Population attributable fraction (PAF) was greatest for metabolic disorders (32%), followed by HCV (20.5%), alcohol (13.4%), smoking (9%), HBV (4.3%), and genetic disorders (1.5%).

• PAF for all factors combined was 59.5%.

• PAFs differed by race/ethnicity and sex.

• Metabolic disorders had the largest PAF among Hispanics (39.3%) and whites (34.8%).

• HCV had the largest PAF among blacks (36.1%) and Asians (29.7%).

• From 2000 to 2011, the PAF of metabolic disorders increased from 25.8% to 36%, while the PAFs of alcohol-related disorders and HCV remained stable.

Citation: Makarova-Rusher OV, Altekruse SF, McNeel TS, et al. Population attributable fractions of risk factors for hepatocellular carcinoma in the United States. [Published online ahead of print March 21, 2016]. Cancer. doi:10.1002/cncr.29971.